JPH01209298A - Energy recovery method in electrically driven bucket work machine - Google Patents

Abstract

PURPOSE:To effectively utilize dropping energy of a bucket by accumulating the dropping energy of the bucket in a flywheel as rotary energy and regenerating it to electric energy, when the bucket is wound up, to be supplied to a bucket motor. CONSTITUTION:In the time of winding down, the first-third controllers 10, 11, 19 are placed in a flow condition of direction in a broken line by a lever switch unit 14, while an opening and closing switch 21 is turned off. Accordingly, bucket winding up and opening and closing motors 3, 4 perform generating action, and their regenerated current is converted into AC power by the controllers 10, 11 thereafter supplied to a dummy load motor 16 through the controller 19, rotating a flywheel 18. Next, when a bucket is controlled being wound up, the controllers 10, 11, 19 are placed in a flow condition of full line, and the switch 21 is turned on. Here, by an inertia turning effect of the flywheel 18, the motor 16 is driven rotating, and it performs generating action. DC power of the motor 16 is converted into AC power by the controller 19 thereafter joining AC power from a generator 6, and the AC power is converted into DC power by the controllers, 10, 11 and supplied to both the motors 3, 4.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for recovering energy when a bucket is lowered in an electric bucket working machine such as a grab dredging machine.
II.

[Conventional technology]

In electric bucket work machines, the bucket drive drum is hoisted by a bucket motor (usually a DC motor) powered by a generator driven by the engine, and when the bucket is lowered, the bucket motor acts as a generator. By Bucket!・I am trying to obtain braking force against descent.

Conventionally, the electric energy (regenerative current) generated by the power generation action of the bucket motor is sent to a dummy load resistor and released as thermal energy to the outside.

[Problem to be solved by the invention]

However, with this method, the energy when the bucket is lowered cannot be used effectively, which not only results in wasted energy, but also requires equipment such as cooling iJ equipment to counter the heat generated by the dummy load resistor. There was a waste.

Therefore, the present invention provides an energy recovery method for a bucket working machine that can recover and effectively utilize the energy of bucket descent.

[Means for Solving the Problems] The present invention provides an electric bucket working machine in which a bucket drive drum is rotationally driven by a bucket motor whose power source is a generator driven by an engine. The electric power generated by the power generation action is supplied to the dummy load motor, which rotates the flywheel, and when the bucket is hoisted up after the bucket is lowered, the dummy load motor is rotated by the inertial rotational force of the flywheel. The electric power generated by the electric power generation action of the motor is combined with the electric power from the generator and supplied to the bucket motor.

[Effect]

In this way, the bucket lowering energy is stored in the flywheel as rotational energy, and when the bucket is hoisted, this rotational energy is regenerated into electrical energy and supplied to the bucket motor, so that the bucket lowering energy is effectively used. Therefore, the power burden on the generator, which is the main power source, is reduced,
Therefore, the capacity of the generator can be small. Furthermore, the cold n1 equipment that was conventionally required is no longer necessary.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a grab-dropping work machine is taken as an example of application.

This grab dredging machine uses a grab bucket (not shown).
It is equipped with a bucket hoisting drum 1 for hoisting the entire bucket, and a bucket I/opening/closing drum 2 for opening/closing the bucket. It is designed to be rotationally driven by 4. 5 is an engine, and 6 is an alternating current generator driven by the engine 5. Using the generator 6 as a power source, the bucket hoisting motor 3 is driven in the bucket hoisting direction, and the bucket opening/closing motor 4 is driven in the bucket closing direction. .

The motor circuits 8 and 9 connecting the power supply circuit 7 of the generator 6 and both motors 3 and 4 each have a first thyristor having a gated bidirectional thyristor as a main element. A second controller 10.11 is provided, which performs AC-DC conversion and current direction control between the generator 6 and both motors 3, 4.

The double-sided TIL device 10.11 is connected to the lever switch device 14 via a command circuit 12.13.

This lever switch device 14 includes a bucket operating lever 1
This lever switch device 1 operates in conjunction with the operation of 5.
4 to both controllers 10 and 11, when the lever 15 is operated to the hoisting position, the current direction flows from the power supply circuit 7 side to the motor circuits 8 and 9 side as shown by the solid line arrow A in the figure. (referred to as the positive direction) and an AC to DC conversion command are issued, and when the lever 15 is operated to the lower position, the motor circuits 8 and 9 move from the motor circuits 8 and 9 side to the power supply circuit 7 side as shown by the broken line arrow in the figure. A current direction command (hereinafter, this direction will be referred to as a reverse direction) and a DC→AC conversion command are issued.

On the other hand, a dummy load motor 16 which is a DC motor is connected to the power supply circuit 7 in parallel with the motor circuits 8 and 9 via a motor circuit 17, and a flywheel 18 is attached to the rotating shaft of the dummy load motor 16. ing. The motor circuit 17 also includes a first motor circuit 8.9 of the motor circuit 8.9. Like the second controller 10.11, the switch device 1 is operated by a lever.
A third controller 19 whose main element is a bidirectional gated thyristor that performs AC-DC conversion and current direction control in response to commands from the controller 4 is provided. 20 is a command circuit that connects this third controller 19 and the lever switch device 14.

Further, a frontage 1 switch 21 is provided at a position closer to the generator 6 than the connection point with the dummy load motor motor circuit 17 in the power supply circuit 7. This 17i1 close switch 21 is connected to the lever switch device 14 via a command circuit 22, and is turned on when the lever 15 is hoisted up and turned off when the lever 15 is hoisted down.

In the actual circuit, the power supply circuit 7 and each motor circuit 8, 9.17 are provided with well-known accessory equipment such as a breaker, reactor, slip ring, etc., but these are not shown here to simplify the drawing. illustration is omitted.

Next, the effect will be explained.

When the operating lever 15 is operated to lower the bucket with the bucket hoisted up and stopped in the air, a command from the lever switch device 14 causes the first... The second and second controllers 10 and 11 are in a reverse flow state as indicated by broken arrows, and the third controller 19 is in a forward flow state as indicated by a broken arrow. Further, the open/close switch 21 is turned off.

Therefore, at this time, the power of the generator 6 is
The energy is not supplied to the 111 closed motors 3 and 4, and these motors 3.4 are rotated by the bucket lowering energy to generate electricity.

The current generated by the power generation action of both septa-ta 3.4,
That is, as shown by arrow 2, the regenerative current is converted into alternating current by the first and second controllers 10.11, and then supplied to the dummy load motor 16 via the third controller 19. The motor 16 is driven and the flywheel 18 rotates.

In this way, when the bucket descends, the energy of its descent is stored in the flywheel as rotational energy.

When the bucket is lowered and the lever 15 is operated to the hoisting position, the first. Both the second controllers 10 and 11 are in a forward flow state as indicated by the solid arrow A, and the 3111III controller 19 is in a reverse flow state as indicated by the solid arrow H. Further, the interval m switch 21 is turned on.

At this time, the dummy load motor 16 is rotationally driven by the inertial rotational force of the flywheel 18, and the motor 16 now performs a power generation action. This dummy load motor 16
The iiiI current generated by the 3rd vJIXI generator 19 is converted into alternating current by the 3rd vJIXI generator 19, as shown by the arrow, and then merges with the current from the generator 6, and this combined current flows into the 1st vJIXI current. Second
It is converted to DC by both controllers 10 and 11, and the bucket is hoisted.
It is supplied to both the opening and closing motors 3 and 4.

In this way, the energy of the bucket falling is transferred to the flywheel 1
8 is stored as rotational energy, and when the bucket is hoisted, this rotational energy is regenerated into electrical energy, and the bucket is hoisted.
This is effectively used as driving power for both the opening and closing motors 3 and 4.

By the way, it is possible to use AC motors for the bucket winding, opening/closing motors 3 and 4, and dummy load motor 16, and in this way, the AC-DC conversion function of each controller 10, 11, 19 is unnecessary. Become.

[Effects of the Invention] As described above, according to the present invention, instead of converting the falling energy of the bucket into heat and releasing it to the outside as in the conventional case, the energy of the bucket falling is stored in the flywheel as rotational energy, and this flywheel is used when hoisting the bucket. The rotational energy of the wheel is regenerated into electrical energy and effectively used as driving power for the bucket drive motor (bucket hoisting, opening/closing motor in the case of grab dredging machines), resulting in good energy efficiency.

That is, the power burden on the generator during bucket hoisting is reduced, and the capacity of the generator can be reduced.

Further, there is no need for cooling equipment to counter the heat generated by the dummy load resistor, which was conventionally necessary, and the synergistic effect of these makes it possible to reduce the initial A full cost and running cost.

[Brief explanation of the drawing]

The figure is a schematic circuit configuration diagram showing an embodiment in which the present invention is applied to a grab dredging machine. DESCRIPTION OF SYMBOLS 1... Bucket hoisting drum as a bucket driving drum, 2... Bucket opening/closing drum, 3... Bucket hoisting motor as a bucket driving motor, 4... Bucket opening/closing motor, 5... Engine, 6... Generator, 15... Bucket operating lever, 16... Dummy road motor, 18... Flywheel. Patent applicant Kobe Steel, Ltd. Representative Patent attorney Etsushi Kotani Patent attorney
Long 1) Masamukai Patent Attorney Yasuo Itaya

Claims (1)

[Claims] 1. In an electric bucket work machine in which a bucket drive drum is rotationally driven by a bucket motor whose power source is a generator driven by an engine, electric power generated by the power generation action of the bucket motor when the bucket is lowered is The power is supplied to the dummy load motor, which rotates the flywheel, and when the bucket is hoisted up after the bucket is lowered, the inertial rotational force of the flywheel rotates the dummy load motor. A method for recovering energy in an electric bucket working machine, characterized in that the electric power is combined with the electric power from the generator and supplied to the bucket motor.